One IP address block is much slower to load pages, have a TTFB of ~10-15 seconds on many websites some are hosted on cloudflare.
While another public IP address block is what should be expected ~ <1ms speed of TTFB when loading web pages.
The only thing that changes when loading the pages is the public IP address block that the IP address is contained within. The DNS, firewall, private IP address, etc. are the same. Just the public IP addressing changes.
Any idea on what the cause is? How can this be fixed?